This invention provides a starting material useful for the preparation of a hydrochlorofluoroolefin (HCFO) compound (cis-1233zd) which has negligible ozone depletion potential (ODP) and low global warming potential (GWP) and is suitable for use in applications such as blowing agents, solvents, and the like.
As described above, this invention is directed to processes for the formation of 233da, a compound used in the production of cis-1-chloro-3,3,3-trifluoropropene, which may be designated as HCFO-1233zd (Z), 1233zd (Z), or cis-1233zd. The compound 1233zd (Z) is a low global warming compound that has applications as a replacement for high global warming materials, for example in foam blowing and aerosol propellant applications.
Processes for converting halogenated hydrocarbons with HF into fluorine substituted species are known. The reactivities of different halogenated groups such as CX3, CHX2, CH2X (X═Cl, Br, I) are different toward the HF/metal halides under certain conditions. By choosing an appropriate metal catalyst and reaction temperature, the group CX3 can be transferred into CF3 group without affecting the other halogenated groups in the same molecule.
The compound 233da can be prepared by the following sequence of reactions;
(a) chlorination of 1,1,1-trifluoropropane to yield 1,1,1-trifluoro-3,3-dichloropropane,
(b) dehydrochlorination of 1,1,1-trifluoro-3,3-dichloropropane to yield 1233zd; and
(c) chlorination of 1233zd to produce 233da.
See, J. Am. Chem. Soc., 64: 1157 (1942), the disclosure of which is hereby incorporated herein by reference.